The Ork guide I tried to write became obsolete as I was writing it, which was really disheartening. At some point in my revisions, I just ran of out gas, and couldn't work up the energy to continue.
Probably because it's lame now, by my reading (of an online resource, since I don't have the book). They don't appear to have any shooting that's worth having, and their melee attacks don't let them use the cool halberd more than once. You get two powers from a discipline that seems...lackluster? Like, a flying dreadnought is still awesome, but the other powers seem largely unhelpful to me. At least, from a self-buff angle. No good attack spells to have as alternatives to just using Smite, and the best powers look to be giving a unit a 5++ (which is fine, but boring) and giving a unit 'extra melee hit on 6s', which you'll only get mileage out of on a unit with way more attacks than the Dread has itself.
Which is a total shame. Part of the reason I played Blood Angels back in 5th was the Librarian Dread, which was the coolest model I owned, give or take a kitbash. Or my Ironclad, actually.
...Why don't Orks have multiple fancy dreads? Or just...ones with unique and interesting weapons? This is a travesty.